Protective layers for mass-produced objects have to satisfy various requirements. Firstly they should be easy to apply to the objects and should not slip during transport. Furthermore, these protective layers need to be easily removed again before the objects undergo further processing. It is moreover advantageous if a rapid application on the corresponding regions of the surface is possible. From the use for mass-produced articles it follows that a low-cost raw material base is advantageous.
WO 2001/46277 discloses a method for producing an adhesive composition containing a degraded ethylene/propylene copolymer, the degradation taking place by thermomechanical stressing of a starting polymer in the presence of a radical former. A further polymer can be added to the degraded ethylene/propylene copolymer before or after it is produced, in order to obtain polymer blends.
WO 2012/013699 describes a method for producing a degraded polyolefin copolymer with an extruder. A specific range of properties of the adhesive and a use are not disclosed.
DE 29705428 describes roofing tiles having a protective layer to prevent damage during transport. The protected regions are the surfaces of the roofing tile which come into contact with other tiles when they are stacked. This protective layer is intended to absorb the vibrations that occur during transport.
The protection of pan tiles with spacers made from plastics is already known. For example, foam parts are placed between the objects to be stacked. These can be fixed by the weight of the other objects, for example. On the other hand, these parts are also provided with a separately applied adhesive coating to prevent them from slipping. The spacers can then be fixed. For example, polystyrene moldings can be used in this way. It is moreover known that polyamide layers can also be used as spacers. These can also be applied directly from the melt and then adhere to the surfaces to be adhesively bonded.
A disadvantage of such methods, however, is that firstly an adequate fixing of the moldings to the objects has to be ensured, while on the other hand these protective layers must be completely removable at least from the visible surfaces of the substrates. A good adhesive strength makes a residue-free separation from the surface very difficult. These materials should have good mechanical stability to prevent them from disintegrating during transport and removal.